CN116488134A - Energy router - Google Patents

Energy router Download PDF

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Publication number
CN116488134A
CN116488134A CN202310521725.4A CN202310521725A CN116488134A CN 116488134 A CN116488134 A CN 116488134A CN 202310521725 A CN202310521725 A CN 202310521725A CN 116488134 A CN116488134 A CN 116488134A
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CN
China
Prior art keywords
voltage
converter
preset
voltage threshold
direct current
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Granted
Application number
CN202310521725.4A
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Chinese (zh)
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CN116488134B (en
Inventor
胡俊峰
王仕城
徐正国
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Beijing Suoying Electric Technology Co ltd
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Beijing Suoying Electric Technology Co ltd
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Priority to CN202310521725.4A priority Critical patent/CN116488134B/en
Priority claimed from CN202310521725.4A external-priority patent/CN116488134B/en
Publication of CN116488134A publication Critical patent/CN116488134A/en
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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/10—Parallel operation of dc sources
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/10—Parallel operation of dc sources
    • H02J1/102—Parallel operation of dc sources being switching converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/10—Parallel operation of dc sources
    • H02J1/106—Parallel operation of dc sources for load balancing, symmetrisation, or sharing
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/10—Parallel operation of dc sources
    • H02J1/12—Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/14—Balancing the load in a network
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
    • H02J7/345—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering using capacitors as storage or buffering devices
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
    • H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J2207/50—Charging of capacitors, supercapacitors, ultra-capacitors or double layer capacitors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • H02J2300/26—The renewable source being solar energy of photovoltaic origin involving maximum power point tracking control for photovoltaic sources
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/40—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation wherein a plurality of decentralised, dispersed or local energy generation technologies are operated simultaneously
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers

Abstract

The application discloses energy router includes: grid-connected converter, off-grid converter, new energy converter, charge-discharge converter and super capacitor; when the deviation value between the DC bus voltage and the preset DC voltage is larger than or equal to the first voltage threshold and smaller than the second voltage threshold, the off-grid converter performs voltage frequency droop control, the charge-discharge converter performs power droop control, and the grid-connected converter stabilizes the DC bus voltage; when the deviation value is larger than or equal to the first voltage threshold value and smaller than the second voltage threshold value and the voltage of the direct current bus is larger than the preset direct current voltage, the new energy converter performs maximum power tracking sagging control; and when the deviation value is greater than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is smaller than the preset direct current voltage, the new energy converter performs maximum power tracking. Each converter does not communicate with the upper computer, communication delay does not exist, and the direct current bus voltage is detected to be stable when the direct current bus voltage fluctuates.

Description

Energy router
Technical Field
The application relates to the technical field of power electronics, in particular to an energy router.
Background
With the gradual exhaustion of traditional energy sources, new energy sources are increasingly paid attention to. Therefore, the large-scale development of the distributed energy is diversified, the renewable energy is mainly divided into renewable new energy and non-renewable energy, the development and the utilization of solar energy, water energy and wind energy are mainly divided, a large amount of new energy is presented in the form of electric energy, and new challenges are presented to a power grid by the intermittence and uncertainty of the new energy, the rapid development of energy storage technology, the appearance of electric automobiles and the like.
The energy router is a key device for realizing the energy internet, and comprises a direct current bus and a converter, for example, the converter can comprise an inverter, a DCDC converter or a rectifier, etc. The energy router can realize power exchange between various energy sources and the direct current bus.
In the prior art, the energy router and the upper computer are controlled in a low-rate communication mode, but the communication has delay, so that the stability of the energy router is poor. For example, when the power of a load or a new energy source suddenly changes, the direct current bus voltage is easy to run away, and faults are easy to occur.
Disclosure of Invention
In view of this, the embodiment of the present application provides an energy router capable of stabilizing a dc bus voltage when the dc bus voltage fluctuates, and without communication delay.
The application provides an energy router, including: grid-connected converter, off-grid converter, new energy converter, charge-discharge converter and super capacitor; the new energy converter comprises a wind power converter and/or a photovoltaic converter; the charging and discharging converter comprises an energy storage converter and/or a charging pile;
the first end and the second end of the grid-connected converter are respectively used for connecting a power grid and a direct current bus; the first end and the second end of the off-grid converter are respectively used for connecting a load and a direct current bus; the new energy converter, the charge-discharge converter and the super capacitor are all connected with the direct current bus;
when the deviation value between the DC bus voltage and the preset DC voltage is larger than or equal to the first voltage threshold and smaller than the second voltage threshold, the off-grid converter is used for performing voltage frequency droop control, the charge-discharge converter is used for performing power droop control, and the grid-connected converter is used for stabilizing the DC bus voltage;
when the deviation value is larger than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is larger than the preset direct current voltage, the new energy converter is used for carrying out maximum power tracking droop control; when the deviation value is larger than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is smaller than the preset direct current voltage, the new energy converter is used for carrying out maximum power tracking.
Preferably, when the deviation value is greater than or equal to the second voltage threshold and less than the third voltage threshold, the off-grid converter is used for controlling according to the preset voltage and the preset frequency.
Preferably, when the deviation value is greater than or equal to the first voltage threshold and less than the second voltage threshold, and the dc bus voltage is greater than the preset dc voltage, the off-grid converter is configured to perform voltage frequency droop control, and specifically includes:
V OFGref ＝V N +K OFG *(U DC -U UP1 )；
F OFGref ＝F N +K OFG *(U DC -U UP1 )；
V OFGref for a given voltage value F of the off-grid converter OFGref Is a frequency given value of the off-grid converter; u (U) DC Is the voltage of a direct current bus, V N For presetting DC voltage, F N Is a preset frequency; k (K) OFG The droop coefficient is preset for the off-grid converter;
when the deviation value is greater than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is smaller than the preset direct current voltage, the off-grid converter is used for performing voltage frequency droop control and specifically comprises the following steps:
V OFGref ＝V N -K OFG *(U DOWN1 -U DC )；
F OFGref ＝F N -K OFG *(U DOWN1 -U DC )；
U DC -U UP1 the sum of absolute values of U DOWN1 -U DC The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold.
Preferably, when the deviation value is greater than or equal to the second voltage threshold and less than the third voltage threshold, and the dc bus voltage is greater than the preset dc voltage, the new energy converter is used for maximum power tracking droop control.
Preferably, the new energy converter performs maximum power tracking droop control, and specifically includes:
P Pref ＝P’ P-MPPT -K P *(U DC -U UP1 )；
P Pref giving instructions for power of new energy converter, P' P-MPPT U is the maximum power point of the new energy converter DC For DC bus voltage, U DC -U UP1 The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold; k (K) P The droop coefficient is preset for the new energy converter.
Preferably, when the deviation value between the dc bus voltage and the preset dc voltage is greater than or equal to the first voltage threshold and less than the second voltage threshold, and the dc bus voltage is greater than the preset dc voltage, the charge-discharge converter performs power droop control, and specifically includes:
P ref ＝P TC -K*(U DC -U UP1 )；
when the deviation value between the direct current bus voltage and the preset direct current voltage is larger than or equal to the first voltage threshold value and smaller than the second voltage threshold value and the direct current bus voltage is smaller than the preset direct current voltage, the charge-discharge converter performs power droop control and specifically comprises the following steps:
P ref ＝P TC +K*(U DOWN1 -U DC )；
P ref given instructions for power of charge-discharge converter, P TC The power issued to the charge-discharge converter for the master controller; u (U) DC K is a preset droop coefficient of the charge-discharge converter for the direct current bus voltage; u (U) DC -U UP1 The sum of absolute values of U DOWN1 -U DC The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold.
Preferably, when the deviation value between the dc bus voltage and the preset dc voltage is greater than or equal to the second voltage threshold and less than the third voltage threshold, and the dc bus voltage is greater than the preset dc voltage, the charge-discharge converter is charged by power droop control;
and when the deviation value between the DC bus voltage and the preset DC voltage is larger than or equal to the second voltage threshold and smaller than the third voltage threshold, and the DC bus voltage is larger than the preset DC voltage, the charge-discharge converter discharges through power droop control.
Preferably, the off-grid converter is adapted to operate at the nominal voltage and the nominal frequency when the deviation value is less than the first voltage threshold.
Preferably, the new energy converter is adapted to operate at a maximum power point when the deviation value is smaller than the first voltage threshold.
Preferably, when the deviation value is smaller than the first voltage threshold value, the charge-discharge converter is used for charging or discharging according to the power issued by the overall controller.
From this, the embodiment of the application has the following beneficial effects:
the energy router provided by the embodiment of the application comprises not only each converter, but also super capacitors, and the capacity of the super capacitors is large, so that high-rate charge and discharge can be realized, the power fluctuation of the energy router is effectively balanced, the direct-current inertia is increased, and the stability of the energy router is improved. In addition, in the energy router provided by the embodiment of the application, each converter automatically responds to the fluctuation of the voltage of the direct-current bus, and each converter does not need to communicate with an upper computer, so that communication delay does not exist, each converter can directly complete control by detecting the voltage of the direct-current bus, and the fluctuation can be restrained when the voltage of the direct-current bus fluctuates.
Drawings
Fig. 1 is a schematic diagram of an energy router according to an embodiment of the present application;
FIG. 2 is a schematic diagram of another energy router according to an embodiment of the present disclosure;
fig. 3 is a flowchart of grid-connected free control performed by the energy router according to the embodiment of the present application.
Detailed Description
In order to enable those skilled in the art to better understand and implement the technical solutions provided by the embodiments of the present application, the following describes the energy router provided by the embodiments of the present application with reference to the accompanying drawings.
Referring to fig. 1, a schematic diagram of an energy router according to an embodiment of the present application is shown.
The energy router 1000 provided in the embodiment of the present application includes: off-grid converter 300, new energy converter, charge-discharge converter and super capacitor 800; off-grid converter 300 is an AC/DC converter. The new energy converter comprises a wind power converter and/or a photovoltaic converter 500; in fig. 1, the new energy converter includes a photovoltaic converter 500, for example, a first end and a second end of the photovoltaic converter 500 are respectively used for connecting the photovoltaic and the dc BUS. Another energy router shown in fig. 2 includes a wind power converter 400 and a photovoltaic converter 500 as new energy converters; the first end and the second end of the wind power converter 400 are respectively used for connecting wind power and a direct current BUS, wherein wind power refers to a wind generating set. Wind power converter 400 is an AC/DC converter, and photovoltaic converter 500 is a DC/DC converter.
The super capacitor 800 is directly connected with the dc BUS, taking fig. 2 as an example, when the port energies of the 6 converters are unequal, the super capacitor 800 can be charged or discharged to fill the energy gap rapidly, and because the power density of the super capacitor 80 is high, high-rate charging and discharging can be realized, the power fluctuation of the dc BUS of the energy router 1000 can be effectively smoothed, the dc inertia can be increased, and the stability can be improved.
The charge-discharge converter includes an energy storage converter and/or a charging pile 700; in fig. 1, the charge-discharge converter includes a charge pile 700, and the charge pile 700 is a DC/DC converter. In fig. 2, the charge-discharge converter includes an energy storage converter 600 and a charging pile 700, and the energy storage converter 600 is a DC/DC converter. In the embodiment of the present application, a charging pile is described as an example, and it should be understood that the charging pile is only representative of a DCDC converter, and may take electricity from a dc bus to charge a load, or may feed electricity from the load to the dc bus.
The first and second ends of the energy storage converter 600 are used to connect an energy storage battery and a dc BUS, respectively. The first and second ends of the charging stake 700 are used to connect the electric vehicle and the dc BUS, respectively.
The first end and the second end of the off-grid converter 300 are respectively used for connecting a load and a direct current BUS; the new energy converter, the charge-discharge converter and the super capacitor 800 are all connected with the direct current BUS.
In addition, the energy router provided in the embodiment of the present application may further include a grid-connected converter 200, where a first end and a second end of the grid-connected converter 200 are respectively used for connecting a power grid and a dc bus; specifically, the first end of the grid-connected inverter 200 is connected to the grid through a relay K1. Grid-tied inverter 200 is an AC/DC inverter. The energy router 1000 further includes a master controller 100, and the master controller 100 may be in wired communication with the various converters. The overall controller 100 may also communicate with an energy management system EMS. The overall controller 100 is also connected to a human-machine interface (HMI, human Machine Interface). The HMI is used for operation data, status display, and manual control of the energy router.
In addition, the EMS can also carry out wireless communication with the ammeter that the first end of each converter is connected, and each ammeter accomplishes the measurement of electric quantity.
The master controller 100 communicates with the HMI, the EMS and the 6 converters (in a wired communication mode), the master controller 100 receives the HMI and the EMS instructions and issues control instructions to the 6 converters through an algorithm, the master controller 100 can upload real-time states and data of the 6 converters to the HMI and the EMS, and the master controller 100 collects the data of the 6 converters in real time and issues the control instructions. Each port of the energy router 1000 is used as a node, and the EMS can settle accounts for each node in real time, for example, the electric automobile is charged, and payment can be performed. The second end of every converter is equipped with the ammeter, and ammeter gathers electric energy data and gives the collector, and the collector gives the EMS with electric energy data, because electric energy data transmission interval is bigger, should adopt wireless mode to organize the net. The user terminal can communicate with the EMS in real time, and the user terminal inquires the current operation data, the setting mode and the command of the energy router in real time through the background APP.
The energy router 1000 may include the following three modes of operation: grid-connected free control, grid-connected power scheduling control and grid-off free control.
The grid-connected free control means that the grid-connected converter port of the energy router is connected with a power grid, but does not accept power scheduling of the power grid, and other converters operate according to a certain working mode.
The grid-connected power scheduling control refers to that a grid-connected converter port of an energy router is connected with a power grid, the power grid power scheduling is responded preferentially, and other converters operate according to a certain working mode on the premise of guaranteeing the power grid power scheduling preferentially.
The off-grid free control means that the grid-connected converter port of the energy router is disconnected with the power grid, and other converters operate according to a certain working mode.
The energy router provided by the embodiment of the application mainly introduces a specific implementation mode of grid-connected free control.
In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures and detailed description are described in further detail below.
Referring to fig. 3, the figure is a flowchart of grid-connected free control performed by the energy router according to the embodiment of the present application.
The energy router that this application embodiment provided includes: the system comprises an off-grid converter, a new energy converter, a charge-discharge converter and a super capacitor; the new energy converter comprises a wind power converter and/or a photovoltaic converter; the charge-discharge converter comprises an energy storage converter and/or a charging pile.
The first end and the second end of the off-grid converter are respectively used for connecting a load and a direct current bus; the new energy converter, the charge-discharge converter and the super capacitor are all connected with the direct current bus.
S301: when the deviation value between the DC bus voltage and the preset DC voltage is larger than or equal to the first voltage threshold and smaller than the second voltage threshold, the off-grid converter is used for performing voltage frequency droop control, the charge-discharge converter is used for performing power droop control, and the grid-connected converter is used for stabilizing the DC bus voltage; because the energy router performs grid-connected free control, the power scheduling of the power grid is not responded. Grid-tied converters are also used to stabilize the dc bus voltage in the energy router.
The voltage frequency sag control of the off-grid converter is specifically that when the voltage of the direct current bus is larger than the preset direct current voltage, the voltage set value and the frequency set value of the off-grid converter are both increased, and when the voltage of the direct current bus is smaller than the preset direct current voltage, the voltage set value and the frequency set value of the off-grid converter are both decreased. The voltage set value is increased and is equivalent to increasing load, the voltage set value is reduced and is equivalent to reducing load, and similarly, the change of the frequency set value is similar to the change effect of the voltage set value.
In addition, when each converter in the energy router provided by the embodiment of the application performs droop control, incremental droop control is adopted, for example, voltage given value increase avoids voltage given value mutation in a gradual increase mode, causes fluctuation, and continuously and gradually changes to increase. Similarly, the voltage set point is reduced by incremental reduction and gradually reduced, and the frequency set point is changed similarly, and is not repeated here.
The charge-discharge converter adopts power droop control and incremental droop control, so that charge power droop and discharge power droop can be controlled. The given power command is also gradually changed and not suddenly changed, so that smooth power without impact can be ensured, and the stability of the energy router is improved.
Since each converter is connected with the direct current bus, each converter independently controls each converter, and each converter can obtain real-time direct current bus voltage and control according to the magnitude of the direct current bus voltage. In order to perform differential control, the embodiment of the application divides the voltage of the direct current bus into sections, and when the voltage of the direct current bus deviates from a preset direct current voltage, the more unstable the direct current bus is, the larger the fluctuation is. When the voltage of the direct current bus deviates from the preset direct current voltage by a small amount, the direct current bus voltage is indicated to have small fluctuation. When the DC bus voltage fluctuates in a smaller range around the preset DC voltage, the DC bus voltage is considered to be in a stable state, and stable control is not needed.
Since the dc bus voltage may be greater than the preset dc voltage or may be smaller than the preset dc voltage, for convenience of description, the degree of deviation is indicated by using a deviation value of the dc bus voltage from the preset dc voltage, the deviation value is a positive number, the dc bus voltage is greater than the preset dc voltage and is also regarded as being deviated, and the dc bus voltage is smaller than the preset dc voltage and is also regarded as being deviated. And when the deviation value is smaller than the first voltage threshold value, indicating that the direct current bus voltage is in a steady state. And when the deviation value is larger than or equal to the first voltage threshold value and smaller than the second voltage threshold value, the fluctuation of the direct current bus voltage is indicated to be in a sub-steady state.
S302: when the deviation value is larger than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is larger than the preset direct current voltage, the new energy converter is used for carrying out maximum power tracking droop control; and when the deviation value is greater than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is smaller than the preset direct current voltage, the new energy converter is used for carrying out maximum power tracking.
It should be understood that S301 and S302 are not sequential, and each converter is independently controlled according to the dc bus voltage, and do not affect each other.
The control of the new energy converter is different from the control of the charge-discharge converter. When the DC bus voltage is greater than the preset DC voltage and the DC bus voltage is less than the preset DC voltage, the control of the new energy converter is differentiated.
The energy router provided by the embodiment of the application comprises not only each converter, but also super capacitors, and the capacity of the super capacitors is large, so that high-rate charge and discharge can be realized, the power fluctuation of the energy router is effectively balanced, the direct-current inertia is increased, and the stability of the energy router is improved. In addition, in the energy router provided by the embodiment of the application, each converter automatically responds to the fluctuation of the voltage of the direct-current bus, and each converter does not need to communicate with an upper computer, so that communication delay does not exist, each converter can directly complete control by detecting the voltage of the direct-current bus, and the fluctuation can be restrained when the voltage of the direct-current bus fluctuates.
The implementation manner of grid-connected free control of the energy router provided in the embodiment of the application is described in detail below with reference to table 1 and table 2. Analysis of table 1 shows that the control principles of the energy storage converter and the charging pile are similar, and analysis of table 2 shows that the control principles of the photovoltaic converter and the wind-electricity converter are similar.
TABLE 1
TABLE 2
For ease of understanding, the meaning of each parameter in tables 1 and 2 is first described below.
U DC -per unit value of dc bus voltage;
U UP1 ，U UP2 ，U UP3 the three voltage thresholds are all constants larger than 1, and U UP1 <U UP2 <U UP3 ；
U DOWN1 ，U DOWN2 ，U DOWN3 The three voltage thresholds are all constants smaller than 1, and U DOWN3 <U DOWN2 <U DOWN1 ；
MPPT- -maximum Power Point tracking (Maximum Power Point Tracking);
definition: the current (energy) flows into the energy router in a positive direction and flows out in a negative direction;
V N -rated ac voltage of the system;
F N -nominal ac frequency of the system;
V OFGref -AC/DC off-grid converter AC voltage given;
F OFGref -the AC/DC off-grid converter AC frequency is given;
K OFG -AC/DC off-grid converter droop coefficients;
P OFG -AC/DC off-grid converter current power;
P WPref -an AC/DC wind power converter power given command;
P’ WP-MPPT AC/DC wind power converter in a stable region (U DOWN1 <U DC <U UP1 ) Is the maximum power point of (2);
P WP-MPPT -maximum power point of AC/DC wind power converter;
K WP -AC/DC wind power converter droop coefficient;
P WP-TC -the power provided to the wind power converter under the master controller (TC);
P PVref -DC/DC photovoltaic converter power given command;
P’ PV-MPPT DC/DC photovoltaic converter in the stable region (U DOWN1 <U DC <U UP1 ) A maximum power point;
P PV-MPPT -DC/DC photovoltaic converter maximum power point;
K PV -DC/DC photovoltaic converter sag factor;
P PV-TC -the power provided to the photovoltaic converter under the master controller (TC);
P BATref -a DC/DC energy storage converter power given command;
P BAT-TC -the power provided to the energy storage converter under the control of the master controller (TC), positive values representing discharge and negative values representing charge;
K BAT -a DC/DC energy storage converter droop coefficient;
P BAT -current power of the DC/DC energy storage converter, positive values representing discharging and negative values representing charging;
P BAT-N -DC/DC energy storage converter power rating;
P EVref -a charging pile power given instruction;
P EV-TC -the power provided to the charging pile under the general controller (TC), positive values representing discharging and negative values representing charging;
P EV-ChgMax -maximum chargeable power of electric vehicle;
P EV-DChgMax -maximum power that can be put in an electric vehicle;
K EV -a charging pile sag factor;
P EV charging pile current power, positive value indicates discharging, and negative value indicates charging.
The control mode of the off-grid converter is described first, and when the deviation value is greater than or equal to the second voltage threshold and smaller than the third voltage threshold, the off-grid converter is used for controlling according to the preset voltage and the preset frequency. I.e. no droop control is performed but the inversion is performed at maximum voltage and maximum frequency, see in particular table 1, v OFGref ＝V N +K OFG *(U UP2 -1)，F OFGref ＝F N +K OFG *(U UP2 -1)。
When the deviation value is greater than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is greater than the preset direct current voltage, the off-grid converter is used for performing voltage frequency droop control and specifically comprises the following steps:
V OFGref ＝V N +K OFG *(U DC -U UP1 )；
F OFGref ＝F N +K OFG *(U DC -U UP1 )；
V OFGref for a given voltage value F of the off-grid converter OFGref Is a frequency given value of the off-grid converter;U DC is the voltage of a direct current bus, V N For presetting DC voltage, F N Is a preset frequency; k (K) OFG The droop coefficient is preset for the off-grid converter;
when the deviation value is greater than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is smaller than the preset direct current voltage, the off-grid converter is used for performing voltage frequency droop control and specifically comprises the following steps:
V OFGref ＝V N -K OFG *(U DOWN1 -U DC )；
F OFGref ＝F N -K OFG *(U DOWN1 -U DC )；
U DC -U UP1 the sum of absolute values of U DOWN1 -U DC The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold.
The control mode of the new energy converter is introduced below, and the new energy converter is used for carrying out maximum power tracking droop control when the deviation value is larger than or equal to the first voltage threshold value and smaller than the second voltage threshold value and the voltage of the direct current bus is larger than the preset direct current voltage; when the deviation value is larger than or equal to the first voltage threshold and smaller than the third voltage threshold and the DC bus voltage is larger than the preset DC voltage, the new energy converter is used for controlling the maximum power tracking sagging.
The new energy converter carries out maximum power tracking droop control and specifically comprises the following steps:
P Pref ＝P’ P-MPPT -K P *(U DC -U UP1 )；
P Pref giving instructions for power of new energy converter, P' P-MPPT U is the maximum power point of the new energy converter DC For DC bus voltage, U DC -U UP1 The absolute value of (a) is greater than or equal to the first voltage threshold and less than the third voltage threshold; k (K) P The droop coefficient is preset for the new energy converter.
The control mode of the charge-discharge converter is described below, the charge-discharge converter comprises an energy storage converter and a charge pile, the control principle is similar, and the specific reference can be seen in table 1. When the deviation value between the DC bus voltage and the preset DC voltage is greater than or equal to the first voltage threshold and smaller than the second voltage threshold, and the DC bus voltage is greater than the preset DC voltage, the charge-discharge converter performs power droop control, and specifically comprises the following steps:
P ref ＝P TC -K*(U DC -U UP1 )；
when the deviation value between the direct current bus voltage and the preset direct current voltage is larger than or equal to the first voltage threshold value and smaller than the second voltage threshold value and the direct current bus voltage is smaller than the preset direct current voltage, the charge-discharge converter performs power droop control and specifically comprises the following steps:
P ref ＝P TC +K*(U DOWN1 -U DC )；
P ref given instructions for power of charge-discharge converter, P TC The power issued to the charge-discharge converter for the master controller; u (U) DC K is a preset droop coefficient of the charge-discharge converter for the direct current bus voltage; u (U) DC -U UP1 The sum of absolute values of U DOWN1 -U DC The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold.
When the deviation value between the voltage of the direct current bus and the preset direct current voltage is larger than or equal to the second voltage threshold and smaller than the third voltage threshold, and the voltage of the direct current bus is larger than the preset direct current voltage, the charge-discharge converter charges through power droop control, namely the battery is ensured to be charged at the moment, and energy flows from the direct current bus to the battery; for example, the energy storage converter performs power droop control to charge P BATref ＝P BAT-TC -K BAT *(U DC -U UP1 ). Charging pile power droop control to charge P EVref ＝P EV-TC -K EV *(U DC -U UP1 )*P EV-ChgMax 。
When the deviation value between the voltage of the direct current bus and the preset direct current voltage is larger than or equal to the second voltage threshold and smaller than the third voltage threshold, and the voltage of the direct current bus is larger than the preset direct current voltage, the charge-discharge converter discharges through power droop control, and at the moment, the discharge of the battery, namely the energy flowing from the battery to the direct current bus, is ensured.
For example, the energy storage converter performs power droop control to discharge P BATref ＝P BAT-TC +K BAT **(U DOWN1 -U DC ). Charging pile power droop control to discharge P EVref ＝P EV-TC +K EV *(U DOWN1 -U DC )*P EV-DChgMax 。
The off-grid converter is configured to operate at a nominal voltage and a nominal frequency when the offset value is less than the first voltage threshold.
When the deviation value is smaller than the first voltage threshold value, the new energy converter is used for working at the maximum power point, namely the maximum power point MPPT (P 'of the photovoltaic converter' PV-MPPT ) Maximum power point MPPT (P 'of wind power converter' WP-MPPT )。
And when the deviation value is smaller than the first voltage threshold value, the charge-discharge converter is used for charging or discharging according to the power issued by the overall controller. For example, the energy storage converter may be charged or discharged (controlled by an instruction) P BATref ＝P BAT-TC . Charging pile can charge and discharge (receive instruction control) P EVref ＝P EV-TC 。
In addition, each converter requires shutdown when the offset value is greater than the third voltage threshold.
Off-grid converter: DC bus is U DOWN1 ≦U DC <U UP1 Off-grid inversion with load at rated voltage and rated frequency in the range, when U UP1 ≦U DC <U UP2 The off-grid converter is switched into V/F sagging control, V OFGref ＝V N +K OFG *(U DC -U UP1 )，F OFGref ＝F N +K OFG *(U DC -U UP1 ) Given an increase in the inversion voltage and inversion frequency, when U UP2 ≦U DC <U UP3 The converter is turned to inverter at maximum voltage and maximum frequency, when U DOWN2 ≦U DC <U DOWN1 The converter is shifted to V/F droop control, V OFGref ＝V N -K OFG *(U DOWN1 -U DC )，F OFGref ＝F N -K OFG *(U DOWN1 -U DC ) Given a reduction in the inverter voltage and inverter frequency, when U DOWN3 ≦U DC <U DOWN2 The converter minimum voltage and minimum frequency inverts and the other voltage range converters are shut down. The rise (decrease) of the inversion voltage and the frequency is equivalent to the increase (decrease) of the load, and the voltage of the direct current bus is U DOWN3 ≦U DC <U UP3 The range is continuously changed, the invention adopts the incremental V/F droop control, and the inversion voltage is given by V OFGref Given F of inversion frequency OFGref Is also continuously changed, avoids the abrupt change of instructions and can improve the stability of the system.
AC/DC wind power converter: when U is DOWN3 ≦U DC <U UP1 The wind power converter is in an MPPT mode; when U is UP1 ≦U DC <U UP3 The wind power converter works in an increment MPPT sagging mode and has a power instruction P WPref ＝P’ WP-MPPT -K WP *(U DC -U UP1 ) When the MPPT output maximum power is greater than the actually required power (P WP-MPPT >P WPref ) Reducing the output power of wind power to P according to droop characteristics WPref And when the MPPT output maximum power is lower than the actually required power (P WP-MPPT <P WPref ) Wind power is according to the maximum power P at the moment WP-MPPT And outputting. The power output of the wind power converter is continuously changed in the full direct current bus range, the output power is smooth and has no impact, and the system stability can be improved.
DC/DC photovoltaic converter: the control strategy is consistent with the strategy of the AC/DC wind power converter, and is not repeated.
DC/DC energy storage converter: when U is DOWN1 ≦U DC <U UP1 When the energy storage converter receives the charge and discharge instructions and the power instructions P of the master controller BATref ＝P BAT-TC The method comprises the steps of carrying out a first treatment on the surface of the When U is UP1 ≦U DC <U UP2 When the energy storage converter changes into increment powerSag control, provided P BAT-TC Is positive, i.e. battery discharge, power command P BATref ＝P BAT-TC -K BAT *(U DC -U UP1 )，P BATref The given value is reduced along with the rising value of the DC bus voltage, the discharge power is reduced, and P BATref Decreasing to a negative value becomes charged, provided that P BAT-TC Is negative, i.e. charged, power command P BATref ＝P BAT-TC -K BAT *(U DC -U UP1 )，P BATref The given value is reduced along with the rising of the value of the DC bus voltage, and the charging power is increased; when U is UP2 ≦U DC <U UP3 When the energy storage converter is in a charging state, the charging power is given by P BATref ＝P BAT-TC -K BAT *(U DC -U UP1 ) Sag factor satisfies P BAT-N ≦K BAT *(U UP2 -U UP1 ) The objective is to pull down the dc bus voltage by having to charge and absorb energy from the dc bus when the dc bus voltage fluctuates in order to vary the power above the nominal value, which may be in a discharge state when the sag factor is too small.
When U is DOWN2 ≦U DC <U DOWN1 Turning to power delta power droop control, if P BAT-TC Is positive, i.e. battery discharge, power command P BATref ＝P BAT-TC +K BAT *(U DOWN1 -U DC )，P BATref The given value increases with decreasing value of DC bus voltage, increasing discharge power, if P BAT-TC Is negative, i.e. battery charging, power command P BATref ＝P BAT-TC +K BAT *(U DOWN1 -U DC )，P BATref The given value is increased along with the decrease of the value of the DC bus voltage, the charging power is reduced, and P BATref Discharging when turning to positive value; when U is DOWN3 ≦U DC <U DOWN2 The energy storage converter is in a discharge state, and the discharge power is given by P BATref ＝P BAT-TC +K BAT *(U DOWN1 -U DC ) Sag factor satisfies P BAT-N ≦K BAT *(U DOWN1 -U DOWN2 ) The equation is designed to be charged when the sag factor is too small for the variable power to be greater than the nominal value, and to ensure that the dc bus voltage must be discharged when it fluctuates, energy is fed into the dc bus to raise the dc bus voltage.
The power output of the energy storage converter is continuously changed in the full direct current bus range, the output power is smooth and has no impact, and the system stability can be improved.
Charging pile: the control strategy is consistent with the DC/DC energy storage converter strategy and is not described in detail herein.
U DOWN1 ≦U DC <U UP1 When P OG +P OFG +P’ WP-MPPT +P’ PV-MPPT +P BAT +P EV >0, the input energy of the energy router is larger than the output energy, the voltage of the direct current bus is increased, the super capacitor is charged, and the voltage of the direct current bus is U UP1 ≦U DC <U UP3 Within the range of P OG +P OFG +P WPref +P PVref +P BATref +P EVref When the energy source router is=0, the input energy of the energy source router is equal to the output energy, the energy reaches a new balance, and the total controller obtains the current states of the 6 converters in real time through communication and corrects P again BAT-TC And P EV-TC Issued instruction to cause P OG +P OFG +P WPref +P PVref +P BATref +P EVref <0, the input energy of the energy router is smaller than the output energy, the super capacitor discharges, the direct current bus voltage is reduced, and the direct current bus voltage returns to U DOWN1 ≦U DC <U UP1 Within the steady-state region.
U DOWN1 ≦U DC <U UP1 When P OG +P OFG +P’ WP-MPPT +P’ PV-MPPT +P BAT +P EV <0, the input energy of the energy router is smaller than the output energy, the voltage of the direct current bus is reduced, the super capacitor discharges, and the voltage of the direct current bus is U DOWN3 ≦U DC <U DOWN1 Within the range of P OG +P OFG +P WPref +P PVref +P BATref +P EVref When the energy source router is=0, the input energy of the energy source router is equal to the output energy, the energy reaches a new balance, and the total controller obtains the current states of the 6 converters in real time through communication and corrects P again BAT-TC And P EV-TC Issued instruction to cause P OG +P OFG +P WPref +P PVref +P BATref +P EVref >0, the input energy of the energy router is larger than the output energy, the super capacitor is charged, the voltage of the direct current bus is increased, and the voltage of the direct current bus returns to U DOWN1 ≦U DC <U UP1 Within the steady-state region.
Each converter adjusts the power in real time according to the voltage of the direct current bus, and the bottom layer adjustment belongs to quick adjustment, so that the energy router can be ensured to be stable in real time. In addition, the energy router provided by the embodiment of the application can also issue a command from the master controller, the issue of a correction command is completed through communication, a certain delay exists in the communication, the issue command from the master controller is slowly adjusted, and the voltage of the direct-current bus can be returned to U DOWN1 ≦U DC <U UP1 The fast-slow regulation mode can completely adapt to the fast change of the load and the intermittence of new energy power generation, and can improve the stability of the energy router.
In order to increase the stability of the system, the converter bottom layer is added with an incremental sagging control strategy, if the DC bus voltage deviates when the load and the new energy power suddenly change, the system generates new energy balance through the control methods of the incremental sagging and the like, and then the power is redistributed through the master controller, so that the DC bus voltage is restored to a stable area (U DOWN1 <U DC <U UP1 )。
The incremental droop control is to accumulate an instruction generated by a droop algorithm on the basis of the original instruction, so that the instruction is free from mutation, the impact is reduced, the stability of the whole system is improved, and the power droop, the V/F droop and the MPPT droop adopted by the invention all adopt an incremental droop control strategy. In the grid-tie free control operation strategy, if the initial operation region is U, as will be illustrated below DOWN1 <U DC <U UP1 The AC/DC grid-connected converter operates in a stable DC bus voltage mode, the AC/DC off-grid converter inverts the load at rated voltage and frequency, the AC/DC wind power converter operates in an MPPT mode (power is P '' WP-MPPT ) The DC/DC photovoltaic converter operates in MPPT mode (power P' PV-MPPT ) The DC/DC energy storage converter operates in a constant-power charge-discharge mode and responds to a power instruction P issued by the master controller BAT-TC The charging pile operates in a constant-power charging and discharging mode (or is stopped), and responds to a power instruction P issued by the general controller EV-TC 。
When the load of the off-grid converter suddenly increases and the photovoltaic and wind power generation is insufficient, the grid-connected converter outputs stable direct current bus voltage with the maximum power (rectification) and is insufficient to stabilize the constant direct current bus voltage, the direct current bus voltage reduces the discharge of the super capacitor, and the direct current bus voltage reaches U DOWN2 ≦U DC <U DOWN1 In the region, the AC/DC wind power converter and the DC/DC photovoltaic converter operate in MPPT mode, the DC/DC energy storage converter operates in incremental droop control mode, and the power command P is the original power command BAT-TC Increasing the power generated by voltage sag, i.e. P BATref ＝P BAT-TC +K BAT *(U DOWN1 -U DC ) In this way, the power command will not suddenly change to reduce impact, the charging pile is operated in the incremental sagging control mode, the AC/DC off-grid inverter is operated in the incremental sagging control mode, the voltage and frequency are reduced in equal proportion according to the voltage of the DC bus, which is equivalent to load reduction, after the DC voltage reaches new balance, the master controller redistributes the power command according to the current power of each converter, so that the DC voltage is slowly restored to the stable region (U DOWN1 <U DC <U UP1 )。
When the load of the off-grid converter suddenly decreases and the photovoltaic and wind power generation is sufficient, the output of the grid-connected converter with the maximum power (inversion) stabilized direct current bus voltage is insufficient to stabilize the constant direct current bus voltage, the direct current bus voltage increases the super capacitor for charging, and the direct current bus voltage reaches U UP1 ≦U DC <U UP2 In the region, the AC/DC wind power converter and the DC/DC photovoltaic converter are operated inMPPT droop mode (illustrated by wind power, when MPPT output maximum power is greater than actual required power (P WP-MPPT >P WPref ) Reducing the output power of wind power to P according to droop characteristics WPref The method comprises the steps of carrying out a first treatment on the surface of the And when the MPPT output maximum power is lower than the actually required power (P WP-MPPT <P WPref ) Wind power is according to the maximum power P at the moment WP-MPPT Output), the DC/DC energy storage converter operates in an incremental droop control mode at an original power command P BAT-TC Increasing the power generated by voltage sag, i.e. P BATref ＝P BAT-TC +K BAT *(U DOWN1 -U DC ) In this way, the power command will not suddenly change to reduce impact, the same charging pile also operates in the incremental sagging control mode, after the DC voltage reaches a new balance, the master controller redistributes the power command according to the current power of each converter, so that the DC voltage slowly returns to the stable region (U) DOWN1 <U DC <U UP1 )。
According to the energy router provided by the embodiment of the application, the super capacitor is added on the direct current bus, so that the direct current inertia of the energy router can be increased, master-slave control of the master controller and each converter and incremental sagging control of each converter can be adopted for control, the master-slave control redistributes energy at a system steady-state level, the incremental sagging of the bottom layer stabilizes system energy change dynamically, and the converters themselves can reduce abrupt changes, so that the system stability is improved.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. An energy router, comprising: grid-connected converter, off-grid converter, new energy converter, charge-discharge converter and super capacitor; the new energy converter comprises a wind power converter and/or a photovoltaic converter; the charging and discharging converter comprises an energy storage converter and/or a charging pile;
the first end and the second end of the grid-connected converter are respectively used for connecting a power grid and a direct current bus; the first end and the second end of the off-grid converter are respectively used for connecting a load and the direct current bus; the new energy converter, the charge-discharge converter and the super capacitor are all connected with the direct current bus;
when the deviation value between the DC bus voltage and the preset DC voltage is larger than or equal to a first voltage threshold and smaller than a second voltage threshold, the off-grid converter is used for performing voltage frequency droop control, the charge-discharge converter is used for performing power droop control, and the grid-connected converter is used for stabilizing the DC bus voltage;
when the deviation value is larger than or equal to a first voltage threshold and smaller than a second voltage threshold and the voltage of the direct current bus is larger than a preset direct current voltage, the new energy converter is used for carrying out maximum power tracking droop control; and when the deviation value is greater than or equal to the first voltage threshold and smaller than the second voltage threshold and the voltage of the direct current bus is smaller than the preset direct current voltage, the new energy converter is used for carrying out maximum power tracking.
2. The energy router of claim 1, wherein the off-grid converter is configured to control according to a preset voltage and a preset frequency when the deviation value is greater than or equal to the second voltage threshold and less than a third voltage threshold.
3. The energy router according to claim 1 or 2, wherein when the deviation value is greater than or equal to a first voltage threshold and less than a second voltage threshold, and the dc bus voltage is greater than the preset dc voltage, the off-grid converter is configured to perform voltage frequency droop control, and specifically includes:
V OFGref ＝V N +K OFG *(U DC -U UP1 )；
F OFGref ＝F N +K OFG *(U DC -U UP1 )；
V OFGref for a given voltage value F of the off-grid converter OFGref A frequency given value for the off-grid converter; u (U) DC For the DC bus voltage, V N For the preset DC voltage, F N Is a preset frequency; k (K) OFG The droop coefficient is preset for the off-grid converter;
when the deviation value is greater than or equal to a first voltage threshold and smaller than a second voltage threshold, and the voltage of the direct current bus is smaller than the preset direct current voltage, the off-grid converter is used for performing voltage frequency droop control and specifically comprises:
V OFGref ＝V N -K OFG *(U DOWN1 -U DC )；
F OFGref ＝F N -K OFG *(U DOWN1 -U DC )；
U DC -U UP1 the sum of absolute values of U DOWN1 -U DC The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold.
4. The energy router of claim 1, wherein the new energy converter is configured for maximum power tracking droop control when the deviation value is greater than or equal to the second voltage threshold and less than the third voltage threshold, and the dc bus voltage is greater than the preset dc voltage.
5. The energy router of claim 1 or 4, wherein the new energy converter performs maximum power tracking droop control, and specifically comprises:
P Pref ＝P’ P-MPPT -K P *(U DC -U UP1 )；
P Pref giving instructions for the power of the new energy converter, P' P-MPPT U is the maximum power point of the new energy converter DC For the DC bus voltage, U DC -U UP1 The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold; k (K) P And presetting a droop coefficient for the new energy converter.
6. The energy router according to claim 1, wherein when a deviation value between a dc bus voltage and a preset dc voltage is greater than or equal to a first voltage threshold and less than a second voltage threshold, and the dc bus voltage is greater than the preset dc voltage, the charge-discharge converter performs power droop control, and specifically includes:
P ref ＝P TC -K*(U DC -U UP1 )；
when the deviation value between the voltage of the direct current bus and the preset direct current voltage is greater than or equal to a first voltage threshold and smaller than a second voltage threshold, and the voltage of the direct current bus is smaller than the preset direct current voltage, the charge-discharge converter performs power droop control, and specifically comprises:
P ref ＝P TC +K*(U DOWN1 -U DC )；
P ref giving instructions for the power of the charge-discharge converter, P TC The power sent to the charge-discharge converter is issued to the master controller; u (U) DC K is a preset droop coefficient of the charge-discharge converter for the direct-current bus voltage; u (U) DC -U UP1 The sum of absolute values of U DOWN1 -U DC The absolute value of (a) is greater than or equal to the first voltage threshold and less than the second voltage threshold.
7. The energy router according to claim 6, wherein the charge-discharge converter is charged by power droop control when a deviation value between a dc bus voltage and a preset dc voltage is greater than or equal to a second voltage threshold and less than a third voltage threshold, and the dc bus voltage is greater than the preset dc voltage;
and when the deviation value between the DC bus voltage and the preset DC voltage is larger than or equal to the second voltage threshold and smaller than the third voltage threshold, and the DC bus voltage is larger than the preset DC voltage, the charge-discharge converter discharges through power droop control.
8. The energy router of claim 3, wherein the off-grid converter is configured to operate at a nominal voltage and a nominal frequency when the deviation value is less than the first voltage threshold.
9. The energy router of claim 5, wherein the new energy converter is configured to operate at the maximum power point when the deviation value is less than the first voltage threshold.
10. The energy router of claim 6 or 7, wherein the charge-discharge converter is configured to charge or discharge according to the power issued by the overall controller when the deviation value is less than the first voltage threshold.
CN202310521725.4A 2023-05-10 Energy router Active CN116488134B (en)

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